It does sound like your machine is in a bit of a mess ...
I suspect something is eating up your ram (memory) causing it have to using the swap file (on the HDD) constantly which will slow your machine down and may be causing time outs with your printer etc. That could be many things (as ever) but could be due to malware you should definitely try Malwarebytes, it has a very functional free version. As has been said before check task manager to see what is using a lot of memory and look at the start up tab and check how much is being pre loaded and if anything looks suspicious. TBH 4Gb really isnt enough to run Win10 effectively but that's a problem for another day.
The printer may be also failing to print due to a corrupted queue , this link will step you through how to clear that
https://answers.microsoft.com/en-us...ndows-10/c01abbe3-bb32-4ef1-9b40-5a24bb3dc8b7
You can reset Windows to several levels using the recovery app
https://support.microsoft.com/en-gb/help/4026528/windows-reset-or-reinstall-windows-10 , Id go straight to a full reset myself but that could take you a while to get all your programs back on there again so look at the options and take your pick.
If this doesn't work I'd make a windows a fresh Windo
ws 10 installation DVD or usb and start with a nice clean installation and get up to date drivers etrc https://www.microsoft.com/en-gb/software-download/windows10
If I was still selling I'd advise you to buy a more up to day machine lol